Two current conduction in ferromagnetic transition metal alloys: Sn in Fe, Co and Ni

Abstract

The electrical resistivity of dilute alloys of Sn dissolved in Fe, Co and Ni have been measured over the temperature range 4.2-300 K. Large deviations from Matthiessen's rule are observed and these are explained in terms of a model in which electrons of opposite spin conduct in parallel. Similarities in the behaviour of the impurity resistivity for each alloy indicate that the screening mechanism is similar in each system. Evidence is presented which strongly supports the assertion that the screening of the Sn impurity is accomplished predominantly by s and p like electrons. Systematic trends in the impurity residual resistivity (at 4.2 K) in the three alloys examined and in CuSn, indicate the presence of a quasilocalized state near the Fermi level for Sn in Fe and Co, but removed from it in Ni and Cu.